Elsevier Science B.V. Acta Medica Okayama 0009-2614 413 4-6 2005 Fabrication of a logic gate circuit based on ambipolar field-effect transistors with thin films of C60 and pentacene 379 383 EN Eiji Kuwahara Haruka Kusai Takayuki Nagano Toshio Takayanagi Yoshihiro Kubozono Ambipolar field-effect transistor (FET) devices were fabricated with a heterostructure of C60 and pentacene, and their p- and n-channel field-effect mobilities were studied as a function of thickness of pentacene thin-films. The observed dependences of the μ values were interpreted in terms of the morphology of the thin films and the band structure of C60/pentacene heterostructure. A complementary metal-oxide-semiconductor (CMOS) circuit was fabricated by integration of two ambipolar FETs, aiming at realization of a new CMOS inverter circuit composed of FETs with the same device structure. The gain of 4, the threshold voltage of 85 V, and the complex output characteristics were explained on the basis of the properties of the component FET devices. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 87 14 2005 Fabrication of C60 field-effect transistors with polyimide and Ba0.4Sr0.6Ti0.96O3 gate insulators EN Yoshihiro Kubozono Takayuki Nagano Yusuke Haruyama Eiji Kuwahara Toshio Takayanagi Kenji Ochi Akihiko Fujiwara Flexible C60 field-effect transistor (FET) device has been fabricated with polyimide gate insulator on the poly(ethylene terephthalate) substrate, and n-channel normally-off FET properties are observed in this FET device. The field-effect mobility, ?, is estimated to be ~10-2 cm2 V-1 s-1 at 300 K. Furthermore, the C60 FET has been fabricated with high dielectric Ba0.4Sr0.6Ti0.96O3 (BST) gate insulator, showing n-channel properties; the ? value is estimated to be ~10-4 cm2 V-1 s-1 at 300 K. The FET device operates at very low gate voltage, VG, and low drain-source voltage, VDS. Thus these C60 FET devices possess flexibility and low-voltage operation characteristic of polyimide and BST gate insulators, respectively. No potential conflict of interest relevant to this article was reported.

Elsevier Science B.V. Acta Medica Okayama 0009-2614 409 4-6 2005 Fabrication and characterization of field-effect transistor device with C2v isomer of Pr@C82 187 191 EN Takayuki Nagano Eiji Kuwahara Toshio Takayanagi Yoshihiro Kubozono Akihiko Fujiwara A field-effect transistor (FET) device was fabricated with thin films of C2v isomer of Pr@C82. This device apparently showed n-channel normally-on type FET properties, where non-zero current was observed at gate-source voltage of 0 VGS, of 0V. Normally off FET properties were observed by subtraction of the non-zero current from the drain current.Thus the normally on properties are ascribed to the high bulk current caused by the small energy gap ≈0.3 eV. The field-effect mobility for this FET was 1.5 x 10-4 cm2 V-1 s-1 at 320 K, being comparable to those of other endohedral metallofullerene FET devices. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 68 3 2005 Kinetic-spectrophotometric method for the determination of trace amounts of bromide in seawater 951 956 EN Kanchana Uraisin Toshio Takayanagi Mitsuko Oshima Duangjai Nacapricha Shoji Motomizu A novel simple, sensitive and rapid kinetic-spectrophotornetric method is proposed for the determination of trace amounts of bromide. The method is based on its catalytic effect on the oxidation of methylene blue (MB) by hydrogen peroxide in strongly acidic solution. The oxidation reaction is activated by large amounts of chloride and can be monitored spectrophotometrically by measuring the decrease in the absorbance of MB at 746 run. The determination of bromide is performed by a fixed-time method at the first 100 s from the initiation of the reaction. Unlike other kinetic-spectrophotornetric methods for the determination of bromide, the proposed method does not require heating the solution. Bromide can be determined in the range from 80 to 960 mu g l(-1) with the detection limit of 35 mu g l(-1). The relative standard deviation of ten replicate determination of 480 mu g l(-1) bromide was 1.4%. The influence of potential interfering ions was studied. The proposed method was satisfactorily applied to the determination of bromide in seawater without interfering effect from chloride ion. No potential conflict of interest relevant to this article was reported.

Elsevier Science B.V. Acta Medica Okayama 0003-2670 558 1-2 2006 Synthesis of a chitosan-based chelating resin and its application to the selective concentration and ultratrace determination of silver in environmental water samples 246 253 EN Rosi Ketrin Katarina Toshio Takayanagi Mitsuko Oshima Shoji Motomizu A novel chelating resin using chitosan as a base material, ethylenediamine-type chitosan, has been synthesized for the first time in the present study, and applied to the collection/concentration of ultratrace amounts of silver in environmental water samples. In the present study, ultratrace amounts of silver collected on the resin were eluted and determined by ICP-MS. The resin packed in a 1 mL mini column could adsorb silver selectively and quantitatively at a flow rate of 2 mL min(-1) in the wide pH range from 1 to 8, and silver adsorbed on the resin could be easily recovered by passing 1 M nitric acid as an eluent into the column. High adsorption capacity for silver at pH 5, 0.37 mmol mL(-1) of the resin, was achieved, and t(1/2) of the adsorption is less than 5 min. The effect of chloride on the collection of silver was examined by varying chloride concentrations from 10(-4) to 0.75 M; the results showed that the present resin can be used for the collection/concentration of ultratrace amounts of silver in natural waters, as well as seawater. To ensure the accuracy and the precision of the method, CASS-4 near shore seawater reference material from the NRCC has been analyzed. This is not a certified SRM for silver, but has been used for comparative silver analysis by several groups, who report very similar results to those that are reported here. The developed method using ethylenediamine-type chitosan resin gives 0.7 pg mL(-1) of the detection limit when 50-fold enrichment was used. The proposed method was successfully applied to the determination of silver in tap, river, and seawater samples. No potential conflict of interest relevant to this article was reported.

Elsevier Science B.V. Acta Medica Okayama 0003-2670 581 2 2007 Functionalization of chitosan with 3,4-dihydroxybenzoic acid for the adsorption/collection of uranium in water samples and its determination by inductively coupled plasma-mass spectrometry 214 220 EN Akhmad Sabarudin Mitsuko Oshima Toshio Takayanagi Lukman Hakim Koji Oshita Yun Hua Gao Shoji Motomizu A chitosan resin derivatized with 3,4-dihydroxybenzoic acid moiety (CCTS-DHBA resin) was newly synthesized for the collection/concentration of trace uranium by using cross-linked chitosan (CCTS) as base material, and the adsorption behavior of uranium as well as 60 elements on the resin was examined by passing the sample solutions through a mini-column packed with the resin. After the elution of the collected elements on the resin with 1M HNO3, the eluates were measured by inductively coupled plasma-mass spectrometry (ICP-MS). The CCTS-DHBA resin can adsorb several metal cations and several oxoanionic elements at appropriate pH. Among these metal ions, uranium shows an excellent adsorption behavior on this resin. Uranium as UO22+ species can be adsorbed on the resin by chelating mechanism with adsorption capacity of 330 mg g(-1) resin. Through the column treatment, the complete removal of large amounts of alkali and alkaline earth matrices without any loss of adsorption efficiency over prolonged usage were achieved with this resin. The CCTS-DHBA resin was applied to the adsorption/collection of uranium in tap water, river water and seawater samples with satisfactory results. The validation of the proposed method was carried out by analyzing uranium in the standard reference materials of SLRS-4, CASS-4, and NASS-5 after passing through the CCTS-DHBA resin, and the results showed good agreement with the certified values. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 1069 2 2005 Capillary zone electrophoretic studies of ion association between inorganic anions and tetraalkylammonium ions in aqueous-dioxane media EN Julius Mbuna Toshio Takayanagi Mitsuko Oshima Shoji Motomizu Ion association between inorganic anions and symmetrical tetraalkylammonium ions, R4N+ (R = Me, Et, Pr, n-Bu, n-Am, and 2-methyl butyl {isoamyl = iAm}) was investigated using ordinary silica capillary by capillary zone electrophoresis. An improved version of the Williams-Vigh method was used for the first time to measure the mobilities of the inorganic anions. Plots of log K-ass against log dielectric constant in various media, revealed a smaller change in K-ass compared to dielectric constant. These plots suggest that the Bjerrum's equation is inadequate in accounting for the associations of ions in a CZE setup. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 72 5 2007 Sequential-injection on-line preconcentration using chitosan resin functionalized with 2-amino-5-hydroxy benzoic acid for the determination of trace elements in environmental water samples by inductively coupled plasma-atomic emission spectrometry 1609 1617 EN Akhmad Sabarudin Narong Lenghor Mitsuko Oshima Lukman Hakim Toshio Takayanagi Yun-Hua Gao Shoji Motomizu A new chelating resin using chitosan as a base material was synthesized. Functional moiety of 2-amino-5-hydroxy benzoic acid (AHBA) was chemically bonded to the amino group of cross-linked chitosan (CCTS) through the arm of chloromethyloxirane (CCTS-AHBA resin). Several elements, such as Ag, Be, Cd, Co, Cu, Ni, Ph, U, V, and rare earth elements (REEs), could be adsorbed on the resin. To use the resin for on-line pretreatment, the resin was packed in a mini-column and installed into a sequential-injection/automated pretreatment system (Auto-Pret System) coupled with inductively coupled plasma-atomic emission spectrometry (ICP-AES). The sequential-injection/automated pretreatment system was a laboratory-assembled, and the program was written using Visual Basic software. This system can provide easy operation procedures, less reagent consumption, as well as less waste production. Experimental variables considered as effective factors in the improvement sensitivity, such as an eluent concentration, a sample and an eluent flow rate, pH of samples, and air-sandwiched eluent were carefully optimized. The proposed system provides excellent on-line collection efficiency, as well as high concentration factors of analytes in water samples, which results in highly sensitive detection of ultra-trace and trace analysis. Under the optimal conditions, the detection limits of 24 elements examined are in the range from ppt to sub-ppb levels. The proposed method was validated by using the standard reference material of a river water, SLRS-4, and the applicability was further demonstrated to the on-line collection/concentration of trace elements, such as Ag, Be, Cd, Co, Cu, Ni, Ph, U, V, and REEs in water samples. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 23 12 2007 Adsorption behavior of cationic and anionic species on chitosan resins possessing amino acid moieties 1431 1434 EN Koji Oshita Toshio Takayanagi Mitsuko Oshima Shoji Motomizu Chitosan resins modified with amino acids, such as glycine, valine, leucine, and serine, were synthesized for investigating the adsorption behavior of cationic and anionic species, and showed good abilities for the adsorption of trace elements in aquatic media as follows: glycine for lanthanoids at pH 7, leucine for molybdenum at pH 1 - 5, serine for uranium at pH 2 - 7, and amino acids for bismuth at pH 1 - 7. Cationic and anionic species could be adsorbed by a chelating mechanism and an anion-exchange mechanism. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 24 5 2008 Adsorption Properties of Ionic Species on Cross-linked Chitosans Modified with Catechol and Salicylic Acid Moieties 665 668 EN Koji Oshita Toshio Takayanagi Mitsuko Oshima Shoji Motomizu Catechol-type chitosan resin and salicylic acid-type chitosan resin were easily synthesized for use in estimating the adsorption behavior of 34 elements at pH 1 - 7 in aquatic media. The catechol-type chitosan resin could adsorb Cu(II) at pH 3 - 7, In(III) at pH 4 - 6, Pb(II) and lanthanoids at pH 5 - 7, and U(VI) at pH 4 - 7 more effectively than the salicylic acid-type chitosan resin and the cross-linked chitosan resin (base material). Adsorption ability was in the order: catechol-type chitosan resin > salicylic acid-type chitosan resin > cross-linked chitosan resin. No potential conflict of interest relevant to this article was reported.

岡山大学環境管理センター Acta Medica Okayama 0917-1533 17 1995 キャピラリー電気泳動法による環境試料中の無機陰イオンの定量 49 55 EN Toshio Takayanagi Eiko Wada Mitsuko Oshima Shoji Motomizu Several inorganic anions in environmental water samples, such as river, rain, tap, and waste waters, were determined by capillary electrophoresis with indirect photometric UV detection. In this study, the use of a polymer coated silica capillary and an anionic organic photometric reagent realized a stable baseline and short analytical time. Nine kinds of anions, Cl(-), Br(-), NO(3)(-), SO(4)(2-), C(2)O(4)(2-), ClO(4)(-), F(-), HPO(4)(2-), and HCO(3)(-), were well separated and detected within 12 minutes. Calibration graphs for the anions showed a good linearity in the range of 0 to 4x10(-4) mol dm(-3). Detection limits of the anions were 2x10(-6) mol dm(-3) (HPO(4)(2-)) to 4x10(-5) mol dm(-3) (NO(2)(-)). Anions in river water (Zasu river) and waste water (Okayama University, North district) were measured over 5 days. The waste water contained various kinds of anions, at high concentrations with its large variation, when compared with the river water. The proposed method offers a simple, rapid, and accurate analysis of anions in water samples. No potential conflict of interest relevant to this article was reported.

岡山大学環境管理センター Acta Medica Okayama 0917-1533 21 1999 誘導結合プラズマ―質量分析法による環境水中の微量金属の定量 4 10 EN Kyue-Hyung Lee Mitsuko Oshima Toshio Takayanagi Shoji Motomizu Trace metals in water samples, such as tap water, river water, and sea water, were determined by inductively coupled plasma-mass spectrometry (ICP-MS). ICP-MS has sufficient sensitivity to detect even below the concentrations of ppt level, and therefore the samples were not pretreated with a concentration column. Practical samples were diluted by lo-fold with ultrapure water and measured directly by ICP-MS. The measuring time of one sample was 2.5 min, and the data for 30 elements were obtained simultaneously. The concentrations of heavy metals, such as Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Sb, and Pb, in the water samples were in the ranges of 0.05~82ng/ml. Zasu river and Sibukawa (sea water) contained various kinds of metals, and the concentration ranges were spread in a wide range; for example, Mg was 25700 ppb and In was 2 ppt. ICP-MS is found to be a useful and a powerful instrument for trace amounts of elements, and can be applied satisfactorily to the environmental water analysis. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0910-6340 13 5 1997 Thermodynamic Study of Ion-Association Reactions between Aromatic Anions and Tetrabutylammonium Ion in an Aqueous Solution 783 789 EN Toshio Takayanagi Shoji Motomizu A temperature effect on ion-association reactions in an aqueous solution has been studied between nine kinds of aromatic anions and tetrabutylammonium ion (TBA(+)). The ion-association constants (K(ass)) were determined by analyzing the change in the electrophoretic mobility of anions, which was obtained by capillary zone electrophoresis, by a non-linear least-squares method. The mobility of the analyte anions decreased with increasing the amount of TBA(+) added in migrating solutions. The thermodynamic parameters in the reaction were obtained from the change in the K(ass) values by the change in temperature. The values of the entropy change (ΔS°) were positive in the ion-association reactions of all of the anions examined, being in the ranges from 5.8 to 46.1 J K(-1) mol(-1); the contribution of TΔS° in the examined ion associates to the Gibbs free-energy changes is larger than that of enthalpy changes (-ΔT°), except for phthalate ion. The results suggest that some hydrated water molecules were released in the formation of such hydrophobic ion associates, as well as in the cases of previously reported inorganic ion associates. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0910-6340 12 4 1996 Separation and Direct Photometric Determination of Inorganic Anions by Capillary Zone Electrophoresis Using Suppressed Electroosmosis 575 579 EN Toshio Takayanagi Shoji Motomizu A simple, sensitive and separative method for the photometric determination of inorganic anions was developed on the basis of suppressed electroosmosis by using a common silica capillary and a simple migrating solution. During the analysis of analyte anions by capillary zone electrophoresis, electroosmotic flow in a silica capillary was suppressed by using low-pH migrating solutions containing sodium sulfate. The stacking effect of sulfate ion was utilized for analyte concentration. Four kinds of inorganic analyte anions examined were detected in sharp signals, and the separation of a nitrate and a nitrite ion was improved by using the low-pH migrating solution with no decrease in detection sensitivity. Calibration graphs for nitrate and nitrite ions showed good linearity in the concentration ranges from about 10(-5) to 10(-4)mol dm(-3), with the detection limit for nitrate ion 4×10(-6)mol dm(-3). Separations of organic anions, such as aromatic sulfonate and carboxylate ions, were also examined; many of them were well separated by the proposed migrating solution. Those organic anions did not interfere with the determination of the inorganic anions. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0910-6340 13 1 1997 Ion Association Reaction between Divalent Anionic Azo Dyes and Hydrophobic Quaternary Ammonium Ions in Aqueous Solution as Studied by Capillary Zone Electrophoresis 11 18 EN Toshio Takayanagi Shoji Motomizu Ion association properties of four kinds of anionic divalent azo dyes were investigated in an aqueous solution containing hydrophobic quaternary ammonium ions. The dyes used in this study possessed a hydroxy and a sulfonate group, which existed as a divalent anion in an alkaline solution. In capillary electrophoresis measurements, the apparent electrophoretic mobility of the dyes decreased along with an increase in the concentration of quaternary ammonium ion (Q(+)) in a migrating solution. Ion association constants of the dyes with Q(+), K(ass), were determined by a simulation method of the mobility change using a non-linear least square method, when 1:1 ion associates formed. The increase in log K(ass) was about 0.07 log unit per one methylene group; that is, the hydrophobicity of a pairing ion played an important role in the ion association reaction in aqueous solutions, as well as ion association in solvent extraction systems. Nitro groups of the dyes slightly affected the ion association constants, whereas the position of the sulfonate group in the azo dyes showed a significant change in ion association constants. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0910-6340 14 2 1998 Equilibrium Study on the Ion Association of Monovalent and Divalent Naphtholsulfonates with Tetrabutylammonium Ion in an Aqueous Solution by Capillary Zone Electrophoresis 311 315 EN Toshio Takayanagi Shoji Motomizu The ion-association properties of monovalent and divalent naphtholsulfonate ions were investigated with tetrabutylammonium ion (TBA(+)) as a pairing ion in an aqueous solution. The ion-association constants were obtained by analyzing the change in the electrophoretic mobility of naphtholsulfonate ions in the presence of TBA+ by capillary zone electrophoresis; also, the contribution of a hydroxyl group to the ion associability of monovalent and divalent naphtholsulfonate ions, as well as the electrophoretic mobility of the ions, was investigated. The obtained ion-association constants indicate that the positional isomers possessing anionic groups at the β-position of the naphthalene ring are more associable with TBA(+) than those at the α-position, and that the ion associability of the divalent naphtholsulfonates is larger than those of the monovalent ones, except for 1-naphthol-2-sulfonate. The abnormal associability of 1-naphthol-2-sulfonate can be explained by a synergistic increase in the hydrophilicity of the divalent ion. The difference in the ion associability between the monovalent and divalent naphtholsulfonates, 0.16 in log unit on the average, was smaller than that between the naphthalenesulfonate and naphthalenedisulfonate ions, 0.30 log unit on the average. The electrophoretic mobility of the naphtholsulfonate ions obtained in the absence of TBA(+) is compared with each other, and the contribution of the hydroxyl group is discussed on the basis of the hydration behavior of the naphtholsulfonates. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0910-6340 14 6 1998 Direct Photometric Determination of Tungstate Ion in the Etching Solutions by Capillary Zone Electrophoresis 1181 1183 EN Toshio Takayanagi Shoji Motomizu No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0910-6340 16 7 2000 Simultaneous Determination of Trace Elements in River-water Samples by ICP-MS in Combination with a Discrete Microsampling Technique after Enrichment with a Chitosan-based Chelating Resin 731 738 EN Mitsuko Oshima Toshio Takayanagi Shoji Motomizu A new technique for the preconcentration of trace elements and matrix elimination with a chitosan-based chelating resin was proposed as a useful pretreatment prior to a measurement by inductively coupled plasma-mass spectrometry (ICP-MS). A small volume of the sample solution (80 µl) was discretely introduced into a nebulizer of ICP-MS using a segmented flow injection (SFI) system; a maximum of fifteen elements were simultaneously measured by a single injection. A chitosan-based chelating resin containing iminodiacetate (IDA) functional groups was used for matrix elimination and enrichment of analyte metal ions. Several metal ions, such as Al, Fe, Ni, Co, Cu, Zn, Ag, Cd, Pb and U, were quantitatively retained on the IDA chelating resin in a micro-column (resin: 1 ml) at pH 6, whereas Na, K, Mg and Ca were completely eluted from the column by washing with an ammonium acetate solution. The concentrations of 24 and 26 elements in river water certified reference materials, JAC 0031 and JAC 0032, respectively, were determined by the proposed SFI/ICP-MS system after pretreating the samples with the proposed technique, as well as without any pretreatment. The thus-obtained analytical data were evaluated by comparing them with the reference values, as well as with those obtained in other studies. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0910-6340 17 11 2001 Highly Sensitive Determination Method for Total Carbonate in Water Samples by Flow Injection Analysis Coupled with Gas-Diffusion Separation 1285 1290 EN Mitsuko Oshima Yanlin Wei Masaki Yamamoto Hiroki Tanaka Toshio Takayanagi Shoji Motomizu A spectrophotometric method for the determination of total carbonate in water samples was developed. The method is based on the color change of an acid-base indicator in relation to the concentration of permeable gas substances through a membrane. By using a new portable FIA system equipped with a gas-diffusion unit, a highly sensitive and on-site determination of total carbonate in aqueous solutions was investigated. A new color-change system with 4-(2',4'-dinitrophenylazo)-1-naphthol-5-sulfonic acid (DNN5S) was developed. Absorbance changes of the reagent solution were measured at 450 nm with a light-emitting diode (LED) as a light source. A new type of gas-diffusion unit was used, and was constructed with double tubing: the inner tubing was a micro porous PTFE (polytetrafluoroethylene) tubing (1.0 mm inner diameter and 1.8 mm outer diameter, pore size 2 μm, porosity 50%); the outer tubing was made of glass with 2.0 mm inner diameter. The optimized system conditions were as follows: the sample size was 200 μl, the temperature of the air bath for the gas-diffusion unit was 25℃, and the length of the gas-diffusion unit was 15 cm; each flow rate was 0.3 ml min(-1). For measuring carbonate at low concentrations, a method for preparing water with less carbonate was proposed: the carbonate content of the water was decreased down to 5×10(-7) M. The calibration graph was rectilinear from 1×10(-6) M to 10(-3) M, and the detection limit (corresponding to a signal-to-noise ratio of 3) was 1×10(-6) M of carbonate. The relative standard deviation (RSD) of ten measurements of 2.3×10(-5) M Na(2)CO(3) solution was 1.9%. The total carbonate in various kinds of water (such as river, sea, rain, distilled and ultra purified) was determined. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0910-6340 18 9 2002 Equilibrium Analysis of Reactions of Metal-Pyridylazoresorcinolato Chelates with Quaternary Ammonium Ion, Nonionic Surfactant and Polyethylene Glycol in Aqueous Solution by Capillary Zone Electrophoresis 1021 1025 EN Toshio Takayanagi Shoji Motomizu The resolutions of metal-4-(2-pyridylazo)resorcinol chelates by capillary zone electrophoresis (CZE) were investigated in the presence of some interacting reagents; also, equilibrium reactions between the chelates and the interacting reagents were analyzed in an aqueous solution. Among nine metal chelates formed in aqueous solution, the chelates of V(V), Fe(II), Co(III), Ni(II), and Cu(II) were resolved and detected by CZE, while other chelates were decomposed during electrophoretic migration. The electrophoretic mobility of the chelates of Fe(II), Ni(II), and Cu(II) increased with increasing pH of the migrating solution; also, the acid-dissociation constants of these three chelates were determined by analyzing the mobility change. The ion-association constants of the five anionic chelates and pyridylazoresorcinolate ion with quaternary ammonium ions were also determined by analyzing the mobility change. The binding behavior of the ligand and its chelates with nonionic surfactant micelle, as well as with polyethylene glycol, were investigated, and their binding constants were determined through the mobility change. When Brij 35 was used as a nonionic surfactant interacting with the anionic chelates, the FeII chelate decomposed at Brij 35 concentrations over 6.67 mM. The equilibrium constants and the reactivity were compared with each other. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0525-1931 45 7 1996 硫酸イオンの試料イオンに対するスタッキング効果を利用する無機陰イオンのキャピラリー電気泳動/直接吸光分析 697 699 EN Toshio Takayanagi Yasuko Hiroi Shoji Motomizu Stacking effect of sulfate ion on the analysis of inorganic anions by capillary zone electrophoresis was examined during the sample injection period. A used silica capillary was dynamically coated with tetradecyltrimethylammonium bromide (TDTMA(+)Br(-)) to control the electroosmotic flow. Analyte anions were directly detected by photometry at 214 nm. Five kinds of anions, namely bromide, nitrite, nitrate, molybdate, and tungstate, were detected. Anion separation was developed using 4×10(-3) M sodium sulfate in the carrier solution. Peak heights for anions increased along with additional Na(2)SO(4). The stacking effect was more effective for the anions with high mobility than those with low mobility. Calibration graphs for nitrate and nitrite showed good linearity in the concentration range of 10(-6) to 10(-5) M. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0525-1931 46 6 1997 キャピラリー電気泳動法による第四級アンモニウムイオンと一価有機酸イオンとのイオン会合反応の解析 467 475 EN Toshio Takayanagi Eiko Wada Shoji Motomizu Ion-association reactions in an aqueous solution between monovalent aromatic anions and quaternary ammonium ions were analyzed by means of the electrophoretic mobility. The electrophoretic mobility of analytes, such as phenolate, benzoate, benzenesulfonate, 1, 3-benzenedisulfonate, 1- and 2- naphtholate, 1- and 2- naphthalenecarboxylate, and 1-and 2- naphthalenesulfonate, was obtained by capillary zone electrophoresis. The electrophoretic mobility of analyte anions decreased with increasing the concentrations of the quaternary ammonium ions added in migrating solutions. The change in the electrophoretic mobility was analyzed to obtain the ion-association constants (K(ass)) by a nonlinear least-squares analysis method, as well as linear-square analysis methods. The obtained ion-association constants were larger in the anions possessing naphthalene ring than in those possessing benzene ring. The values of K(ass) became larger when more bulky cations were used as a pairing ion, indicating that the hydrophobicity of ions contributed to the ion associability. The ion associablities of β-substituted naphthalene isomers were larger than those of the α-substituted type, which agreed with the acid-dissociation property of the anions. The difference in the K(ass) values among functional groups was small, compared with ion-pair extraction constant (K(ex)) of the ion associates. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0525-1931 47 12 1998 非イオン界面活性剤ミセル存在下におけるトリフェニルメタン系陽イオン染料からトリフェニルメタノール生成の速度論的研究 953 958 EN Toshio Takayanagi Tomoko Miya Shoji Motomizu The formation rates of triphenylmethanols from corresponding cationic triphenylmethane dyes were investigated in the presence of nonionic surfactant micelles, such as Triton X-100, PONPE-20, Brij-35 and Brij-58. The increases in the formation rates of triphenylmethanols with the hydroxide ion in a nonionic micellar solution were almost comparable to that in the presence of a cationic micelle of stearyltrimetylammonium ion. The increase in the rate was largest with Triton X-100, and the rates with the hydroxide ion increased on the order of about 10(2.0)10(3.7) fold compared with those in an aqueous solution. The reaction rates for malachite green and brilliant green increased most significantly among the five dyes examined. The rates also increased along with an increase in the hydrophobicity (lipophilicity) balance of the surfactant molecule. These results indicate that the cationic dyes are adsorbed on the hydrophobic core of the surfactant micelle, and that the formed triphenylmethanols are incorporated in the core. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0525-1931 51 9 2002 1,8-ジアミノナフタレン-3,6-ジスルホン酸骨格を持つ新規水溶性蛍光試薬の合成と銅イオンの高感度定量への応用 785 789 EN Kazuhiro Nomura Mitsuko Oshima Toshio Takayanagi Shoji Motomizu Water-soluble fluorescent reagents, 1,8-di-(toluene-4-sulfonylamino)-naphthalene-3,6-disulfonic acid (BTND) and 1,8-di-(trifluoromethanesulfonylamino)-naphthalene-3,6-disulfonic acid (BTFND), were newly synthesized. The reactivities of these fluorescent reagents to Cu(2+), Ni(2+), Co(2+), Cd(2+), Pb(2+), V(V), Ag(+), Fe(3+), and Mg(2+) were examined. BTFND was reacted with 8 metal ions, except for Pb(2+), to show fluorescence quenching. BTND was selective to Cu(2+), and the fluorescence was quenched quantitatively at pH 7 in an aqueous solution (λ(ex)=360 nm and λ(em)=405 nm). The calibration graph for Cu(2+) with BTND was rectilinear over the concentration range from 0 to 10(-5) M and the detection limit was 2.0×10(-7) M. BTND has many advantages, such as selectivity for Cu(2+), high sensitivity, and a simple procedure. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0525-1931 51 9 2002 2-(5-ニトロ-2-ピリジルアゾ)-5-(N-プロピル-N-スルホプロピルアミノ)フェノールを用いるキャピラリー電気泳動法によるニッケル, 鉄塩中の極微量不純物の定量 791 795 EN Takuji Kagawa Toshio Takayanagi Mitsuko Oshima Shoji Motomizu 2-(5-Nitro-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino)phenol (Nitro-PAPS) was used for a quantitative determination of ultratrace-level metal ions in commercially available metal salts by capillary zone electrophoresis. At pH 7, Nitro-PAPS reacts with various metal ions to form chelate compounds having large molar absorptivities. Although chelate formation is useful for the highly sensitive detection of metal ions, the resolution of the metal complexes is poor at pH 7. Cetyltrimethylammonium bromide was added to suppress any electroosmotic flow. The hydration of nitro groups of a chelating agent and chelates was controlled by the addition of urea. Sodium sulfate was also utilized to sharpen the signals of metal chelates by a field-enhanced stacking effect. As a result, the resolution was improved and the determination of 10-7 M level metal ions was possible. The proposed method was applied to the analysis of metal impurity at ultratrace levels in commercially available nickel and iron salts. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0525-1931 53 1 2004 微量フロー滴定分析法の開発と酸塩基滴定への応用 1 6 EN Hironobu Konishi Toshio Takayanagi Mitsuko Oshima Shoji Motomizu 容量分析法の簡便化，迅速化，自動化及び省力化を含む高機能化を目的として，送液ポンプの流量比に基づくフロー滴定システムの構築と応用について検討した．フロー滴定分析法は，連続して流れる試料液，滴定剤溶液の正確な流量制御を基本原理としている．2台の送液ポンプを用いてそれらの流量を変化させながら試料液（被滴定液）と滴定剤（滴定液）を送液し，流れ内において混合・反応させ，指示薬の変色を用いて試料液中の分析対象物質濃度を流量比から定量する容量分析法である．各種酸塩基滴定を通して本法の性能評価を行い，従来法との比較を行った．酸塩基指示薬としてフェノールフタレイン，あるいはクレゾールレッドを試料液又は滴定剤へ添加したところ，強酸，弱酸を問わず検討したすべての系において直線性の高い検量線が得られた．また，終点検出の相対標準偏差は0.3％未満であった．更に，滴定剤に2種類の指示薬を用いる多塩基酸・多酸塩基の連続滴定法について検討した．炭酸塩の分析ではブロモクレゾールグリーンとフェノールフタレインを指示薬として用い，炭酸イオン，重炭酸イオンに由来する二つの当量点を一試料測定で検出できた．本法を市販されている食酢の分析に適用したところ，従来法により決定した酢酸濃度と良好な一致を得た．1試料測定当たりの廃液量は50 ml程度から100 μl程度まで大幅に低減化することができ，フロー滴定分析法により全操作の自動化，試料・廃液量の大幅な低減化，滴定時間の短縮等の高機能化を達成した． No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0525-1931 53 7 2004 水溶性シッフ塩基へのマージングゾーン誘導体化/逆相分配高速液体クロマトグラフィーによるn-アルキルアミン類の分離定量 723 728 EN Toshio Takayanagi Kuniko Sawai Qiong Li Mitsuko Oshima Shoji Motomizu Separation and determination of n-alkylamines were investigated with anionic aldehydes to form water-soluble Schiff bases by using reversed-phase high-performance liquid chromatography (RP-HPLC). Two labeling reagents of salicylaldehyde-5-sulfonate (SAS) and 4-(4-sulfophenylazo)-1-hydroxy-2-naphthaldehyde (SPAHNA) were investigated. Sample solution containing the analytes and reagent solution were simultaneously injected and merged in the flow line, and water-soluble Schiff bases were formed in the reaction tube with its length of 5 m and at 70°C. The Schiff bases were resolved with water-methanol eluent on a reversed-phase column and photometrically detected. The entire analysis time including on-line derivatization, column separation and detection was accomplished within 25 min with SAS and 18 min with SPAHNA. The determination range for the n-alkylamines are 0∼50 μM with the limit of detections at 0.5∼1.0 μM for SAS and 0.08∼0.20 μM for SPAHNA. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0525-1931 53 9 2004 シアニン系新規合成試薬を用いる陰イオン界面活性剤の定量 919 923 EN Akinori Goto Mitsuko Oshima Toshio Takayanagi Shoji Motomizu For the spectrophotometric determination of anionic surfactants in aqueous media, cationic dyes with a 2,2'-thiacyanine skeleton were newly synthesized. Carbon numbers of 4 and 6 in the n-dialkyl chain combined at the N position of 2,2'-thiacyanine are new compounds. Fundamental information, such as the (p)K(a) values, was obtained. These two compounds and purchased diethyl- and dipropyl-2,2'-thiacyanine were examined for the spectrophotometric determination of an anionic surfactant, DBS. Of these, 3,3'-dihexyl-2,2'-thiacyanine (DHT) showed the best sensitivity. The calibration graph for DBS with DHT was linear up to 1×10(−5) M, and the detection limit was 4×10(−7) M. By a hydrophobic interaction, even a cationic surfactant, Zephiramine, and a nonionic surfactant, Triton X-100, could react with DHT. The ion-association constants for these surfactants with DHT were obtained. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0525-1931 55 9 2006 コンピュータ制御されたフローインジェクション分析装置の開発と環境水中の硝酸イオン，亜硝酸イオン，アンモニウムイオン定量への応用 707 713 EN Yasutaka Joichi Lenghor Narong Toshio Takayanagi Mitsuko Oshima Shoji Motomizu Nobuo Ura Flow injection analysis (FIA) systems with low power consumption and personal-computer control were developed by using solenoid pumps and an LED detector. Both programs for controlling the system and acquiring measurement data were written using LabVIEW. The FIA system was applied to the determination of nitrite ion in river-water samples based on diazotization and coupling reactions. Linear calibration graphs were obtained with the combination of pump(s) and photometric detector in the concentration range of nitrite ion at 0.5∼3.0 × 10−6 M. Nitrate and nitrite ions were also determined simultaneously by the system by using a Cd/Cu reduction column and a by-pass flow. Determination of ammonia in river-water samples was also realized by the system with a modified indophenol reaction. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0525-1931 55 9 2006 誘導結合プラズマ発光分析のためのキレート樹脂を用いる高効率自動前処理濃縮 715 720 EN Takako Yamamoto Sabarudin Akhmad Osamu Noguchi Toshio Takayanagi Mitsuko Oshima Shoji Motomizu An automatically controlled collection/concentration system for ICP-AES was developed. Elements were collected with small chelating disks and chelating resin with the iminodiacetate moiety packed in a line filter. This column was installed in a 6-way valve on the pretreatment system, which could be connected on line to ICP-AES. The flow rate was 1 ml min−1 and conditioning of the chelating disk was carried out by flowing 0.5 M ammonium acetate (pH 5.5) for 2 min, sampling for 5 min and washing for 1 min. Elution was done by passing through 2 M HNO3 at 1.3 ml min−1 for 1 min. Bi, Cd, Co, Cr, Cu, Mn, Ni, Pb and V could be determined with 5.0 ml of the sample solution. The enrichment factors were 3∼15 times and the collection efficiencies were better than 80%. The detection limits (LOD) were from 0.003 for Mn to 0.311 for Bi, which were several 10 to 100-times lower than that of normal LOD of ICP-AES. This method was successfully applied to the determination of these metals in tap and river-water samples. No potential conflict of interest relevant to this article was reported.